I'm a level 50 Paladin with no experience in the coliseum. I don't think I can beat people 1v1 without getting better charms, but maybe 2v2 would be better? Is there anyone that wants to team up with me and try and get me some coliseum skills?

Coli master is among the more important skills, and a paladin is going to have a rough time. Since you're doing melee, make sure you run plenty of focus - dragon rage, strike - and consider stuff like celestial sword, and buffs like haunted fang.